Warmy.io review

Warmy.io warms up and monitors mailboxes. It does not send campaigns, build sequences or store a lead list, and it’s reviewed here as the warmup specialist in this guide, not as a competitor to a full sender. Pricing is no longer public: as of roughly May 2026, Warmy pulled its pricing table and now quotes “B2B Sender” and “B2C Sender” tiers starting “from $49/month” only after a demo call. G2 rates it 4.8 out of 5 from 503 reviews and Capterra 4.8-4.9 from 54-55, the strongest combined score of anything in this guide, for a product that does exactly one job.

What Warmy.io is for

Pair Warmy with any sender, Instantly, Smartlead, Saleshandy and lemlist all come up in its own marketing as common pairings, and it takes over the warmup and ongoing deliverability-monitoring job your sender’s built-in warmup would otherwise handle. Features on every plan include an AI co-pilot called Adeline for deliverability insights, a reputation tracker, Google Postmaster integration, DMARC monitoring, email verification and full API access. Warmy describes its warmup network as 1M-plus mailboxes with a 500K-plus US seed list, a vendor-reported figure, not independently audited.

What’s no longer public about pricing

Warmy’s pricing page used to list five named tiers (Starter through Platinum) billed per mailbox per month, scaling from roughly $49 for about 100 warmup emails a day up to roughly $429 for about 5,000 a day. That table is gone. The current site shows only “B2B Sender,” “B2C Sender” and a custom Enterprise option, each starting “from $49/month,” with the real per-mailbox rate locked behind a sales call. What hasn’t changed is the billing model itself: per mailbox connected, with no unlimited-mailbox plan at any point in Warmy’s history. A 7-day trial with no credit card required is still the easiest way to see current pricing in context, since the trial flow shows plan options even if the public page doesn’t.

Where it frays

The strongest reason to think twice is that every full sender in this category, Smartlead, Saleshandy, Instantly, lemlist, already includes some form of warmup for free inside its own plan. Choosing Warmy on top of one of those means paying for warmup twice, once implicitly in the sender’s subscription and once explicitly per mailbox to Warmy, in exchange for deeper monitoring and diagnostics than most senders’ built-in warmup provides. Reviewers also describe a specific, repeated problem: the warmup sequence silently stopping, or an account disconnecting, while billing kept running regardless, with one cited case over $100 a month charged during a non-functional stretch. A smaller complaint thread says the dashboard is too thin on real-time alerting to catch that kind of failure quickly, and that warmup through a custom SMTP setup or a non-Gmail provider performs worse than Gmail-based warmup.

Who should skip it

Skip Warmy.io if your current sender’s built-in warmup, the kind Smartlead and Saleshandy both include free on every tier, is already keeping your inbox placement healthy; paying per mailbox for a second warmup layer only pays off if you need the deeper diagnostics Warmy adds. Skip it too if pricing transparency matters before a sales call, since the current site won’t quote a real number without one. See the cold email software guide for how it’s positioned next to the senders it’s built to pair with, including Saleshandy and lemlist, and the email deliverability tools guide for how it compares with MailReach, a warm-up tool with published per-mailbox pricing.